J-shaped hooks, commonly referred to as "J-hooks", are well known in various applications for connecting a load to a chain or the like. J-hooks are typically used for towing vehicles, such as by coupling an eye of the J-hook to a tow chain of a recovery vehicle and connecting an arcuate portion of the J-hook to a fixed member of the vehicle to be towed or to a chain attached to such a fixed member.
Many J-hooks, such as those described in U.S. Pat. Nos. 1,459,816 and 2,646,306, are designed exclusively for generally-constant vertical loading conditions associated with suspension of a load. J-hooks designed for vertical suspension loading are generally ill-suited for use in vehicle towing and securement due to their short "reach", this being defined as the distance from an inner radius of the arcuate portion of the J-hook to the center of attachment opening in an eye portion at the opposite end of the J-hook.
Common prior art J-hooks designed for the purpose of towing vehicles have been produced by bending a suitable length of steel rod of a given diameter into the desired J-shape, forming an eye portion with an attachment opening at the top end of the "J", and tapering the tip of the "J". J-hooks of this type have been manufactured using 7/8" diameter bar stock, and have a yield strength of approximate 7,000 pounds.
U.S. Pat. No. 4,171,842 appears to disclose a J-hook for towing vehicles which has a thickened elbow portion to enhance the strength characteristics of the J-hook. Tests conducted by applicant indicate that the J-hook according to this patent has a minimum breaking strength, defined as the loader force at which the J-hook fails or no longer supports the load under standard testing conditions of less than 10,000 pounds.
Still another J-hook for towing vehicles, which is owned by the assignee of the present invention, is shown and described in U.S. Pat No. 5,564,766. This patent discloses a J-hook formed by forging "Micro-Tuff 10" steel available from Chaparral Steel, located in Midlothian, Tex. The aggregate disclosures of the aforesaid U.S. Pat. Nos. 1,459,816, 2,646,306, 4,171,842 and 5,564,766 are hereby incorporated by reference insofar as the structure, material of construction, and uses of such J-hooks are concerned.
It would be generally desirable to provide an improved J-hook having an enhanced strength-to-weight ratio.